High-precision constant temperature and humidity air conditioners (also called constant temperature and humidity air conditioners) that can fully meet the environmental conditions of the computer room are a new type of machine that has gradually developed in the past thirty years.
    High-precision constant temperature and humidity air conditioners for computer rooms have the following characteristics: large air volume, small enthalpy difference, and high sensible heat ratio; the heat load of the computer room varies greatly, usually between 10% and 20%; there are various ways of sending and returning air, including upper air supply, lower air supply, upper return air, lower return air, and side return air, and the commonly used ones are upper delivery and lower return and lower delivery and upper return; high reliability, the control system and functions of high-precision constant temperature and humidity air conditioners for computer rooms are much more complete than those of general comfort air conditioners; year-round operating reliability and all-weather operation.
    Based on the characteristics of high-precision constant temperature and humidity air conditioners for computer rooms, when the purchaser proposes the purchase demand for high-precision constant temperature and humidity air conditioners, it is necessary to pay attention to the differences from the general air conditioner purchase demand. The following factors should be considered when selecting a machine and filling in the purchase requirements:
1. According to the heat generation of the equipment in the computer room, the area of ​​the computer room, the conditions of the computer room (including floor height, sealing, decoration, outdoor unit installation location, etc.), local climatic conditions, etc., estimate the total cooling capacity, total air volume, humidification capacity and other parameters of the computer room air conditioner, and then select the appropriate equipment capacity (a certain equipment backup can be considered).
2. According to the overall structure of the entire building, select the appropriate air conditioning cooling method (air-cooled, water-cooled, dual cold sources, etc.).
3. Combined with the structural characteristics of the computer room itself and user requirements, reasonably select the air supply method. The air supply form of precision air conditioners dedicated to computer rooms is mostly top-send and bottom-return and bottom-send and top-return. When selecting the bottom air supply equipment, the static pressure box under the electrostatic floor is used as the air conditioner. In order to ensure smooth air supply, the height of the electrostatic floor must be guaranteed to be 300㎜. If the top air supply equipment is selected, the hood air supply method can be selected. Generally speaking, the static air height of this type of computer room is above 2.8 meters, and the area of ​​the computer room cannot be too large, otherwise uneven air supply will occur.
4. Energy saving and future operating costs should be considered when selecting the model. From the perspective of energy saving, it is advisable to use a dual-cold source air conditioner, which is an energy-saving air conditioner. The energy-saving power resources are more than 40% more than the simple electric refrigeration air conditioner of the same capacity.
5. Precision air conditioners with purification systems need to consider the requirements for external residual pressure. Systems with precision air conditioning but no purification requirements do not require high external residual pressure for air conditioners, mainly to overcome the supply and return air ducts, valves, diffusers, primary filters, etc. However, systems that have both constant temperature and humidity requirements and purification level control require higher external residual pressure for air conditioning units. Generally, the total system resistance is between 1100Pa-1400Pa, mainly to overcome the resistance of supply and return air ducts, valves, diffusers, primary filters, medium efficiency filters, high efficiency filters, etc. The requirements for external residual pressure need to be considered when selecting the model.